Corals

It has long been recognized
that corals archive isotopic and trace element records in their annual bands of their skeleton
and therefore can be used for the reconstruction of past ocean temperature records if an
appropriate absolute chronology of their growth is established. Using dated corals,
oceanographers and climatologists are now developing "floating" absolute chronologies
for corals and sediments going back several hundreds of years. When completed,
this will enable sea-surface temperature, salinity and the frequency and intensity
of past El Niño events to be reconstructed for different locations and so permit
better predictions of ocean-atmosphere coupling in the future.